Semiconductors are widely used in integrated circuits for electronic devices such as computers and televisions. These integrated circuits typically combine many transistors on a single crystal silicon chip to perform complex functions and store data. Semiconductor and electronics manufacturers, as well as end users, desire integrated circuits that can accomplish more functions in less time in a smaller package while consuming less power. Miniaturization is a common approach to help meet these goals.
With increasing miniaturization, one concern is the thickness of the gate dielectric used in conventional CMOS circuits. The current drive in a CMOS transistor is directly proportional to the gate capacitance. Since capacitance scales inversely with gate dielectric thickness, higher current drive requires continual reductions in thickness for conventional dielectrics. Present technology uses silicon dioxide (SiO.sub.2) based films with thicknesses near 5 nm. However, projections suggest the need for 2 nm (20 .ANG.) films for future small geometry devices.